His death came more than 18 years after he murdered two Mercer University students, Grant Hendrickson and Michelle Cartagena, who were parked at a camping site at Lake Juliette.

Cook's execution was orginally set for 7 p.m. Thursday, but it was delayed three and a half hours while the U.S. Supreme Court considered his final appeal.

He died less than an hour after the high court denied that appeal at 10:35 p.m.

The execution moved forward Thursday after the Georgia Court of Appeals issued a temporary postponement. But the Georgia Supreme Court reinstated it.

From there, it moved to the U.S. Supreme Court for the final consideration.

A media witness to the execution, Will Davis of the Monroe County Reporter said Cook made a final statement while in the death chamber awaiting the lethal injection.

Davis said Cook apologized to the victims' families who were sitting in the witness area adjoining the death chamber, but that he wouldn't ask for their forgiveness because he wasn't able to forgive himself.

Cook called his act "senseless," and after the statement, Davis said Cook declined a final prayer.